The present invention relates to a braking device for a vehicle, and in particular relates to a braking device for a vehicle which can reduce damage caused by vehicle's collision with a front obstacle, which includes an object existing in front of the vehicle or another vehicle traveling in front of the vehicle, by using braking of the vehicle.
Conventionally, a braking device for a vehicle which reduces damage caused by vehicle's collision with another vehicle traveling in front of the vehicle by using braking of the vehicle when the vehicle approaches another vehicle traveling in front of the vehicle (i.e., a front-traveling vehicle) is known.
For example, Japanese Patent Laid-Open Publication No. 2005-82041 discloses an automatic braking device of a vehicle which increases a pedal reaction force of an acceleration pedal (i.e., an accelerator) of the vehicle and operates automatic braking in a case in which the vehicle may possibility collide with an obstacle positioned in front of the vehicle. In this automatic braking device, in a case in which a driver operates the acceleration pedal after the automatic braking is operated, this acceleration pedal's operation is considered as a driver's intentional action, so that an automatic braking control is canceled.
A collision prevention control device which limits starting or accelerating of a vehicle, in a case in which an acceleration pedal is operated mistakenly when an obstacle exists in front of the vehicle, so as to prevent the vehicle from colliding with the obstacle is also known.
For example, Japanese Patent Laid-Open Publication No. 2004-280489 discloses a collision prevention control device in which when a vehicle approaches an obstacle and the distance to the obstacle becomes a specified distance or less while the vehicle stops or travels at a low speed, a throttle opening is limited or an automatic braking is operated so as to limit starting or accelerating of the vehicle.
Herein, it may be considered that both of the conventional braking device for a vehicle disclosed in the former patent document and the conventional collision prevention control device disclosed in the latter patent document are installed to the vehicle.
However, in a case in which the conventional braking device for a vehicle and the conventional collision prevention control device are installed to the vehicle together, there is a problem in that both functions of these devices may not be compatible. For example, in a case in which the acceleration pedal is operated when the distance to the obstacle is the specified distance or less while the vehicle stops or travels at the low speed and the starting or accelerating of the vehicle is limited by the collision prevention control device accordingly, the braking device for a vehicle may recognize that the acceleration pedal's operation is intentional, so that the braking device may cancel the automatic braking control. Thus, there is a problem in that the collision prevention control device may not be able to operate the automatic braking, so that the vehicle may not be able to be stopped properly.